Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alta.

Abstract

Ethanol is a chemically simple compound that produces many well-known effects in humans. The prevailing idea for many years was that ethanol and other alcohols exerted their effects on the central nervous system (CNS) by non-selectively disrupting the lipid bilayers of neurons. However, in recent years, there has been an accumulation of evidence pointing to the importance of ligand-gated ion channels (LGICs) in mediating the effects of ethanol. Of these LGICs, γ-aminobutyric acid type A (GABAA) receptors appear to occupy a central role in mediating the effects of ethanol in the CNS. GABA is the primary inhibitory neurotransmitter in the mammalian CNS, and activation of GABAA receptors by GABA tends to decrease neuronal excitability. This article reviews several aspects of GABAA receptor and ethanol interactions, including the evidence for short- and long-term modulation of GABAA receptors by ethanol and evidence for a GABAA receptor-related genetic component of alcoholism.